Ever since I saw Borgdog's Nobs table I've had an interest in making my own home brew table. I've authored or helped out on over a dozen Visual Pinball EM tables and a few months ago I got the opportunity to help out on a Cuphead table that I really liked. The table has a great theme, fun game play, a good rule set, interesting graphics and a lively sound track. After we got the table released I asked the designer of the table if I could use his resources to make a home brew version of this table and that started up this project.

My first hurdle was learning how to work with Mission Pinball Framework (mpf). The really nice thing about mpf is that it automatically takes care of all of the low level processes like player and ball management, extra balls, multiball and interfacing with OPP boards. The drawback to working with a framework is that it expects exactly what it wants and if you don't give it exactly what it wants, you have problems.

The mpf site has great documentation and the google groups page has a lot of very nice folks to help noobs like myself make progress. After about a month of trial and error (much error) I ended up with a working mpf set of configs. MPF has a "monitor" section that lets you set up an image of the playfield with all of the switches, coils and lights on it and then click on these to see how the game plays which is critical to troubleshooting the configs. The monitor can also display variable values and other data to help sort out how your configs are running.

Since I had played the table many times in its visual pinball format so I knew that it should be a fun table but I wanted to try out the mpf vpx bridge before I bought a donor table and invested a lot of time and money into a project that either wouldn't work out or wouldn't be fun to play. The mpf vpx bridge is a software interface that lets you run your table in mpf while letting vpx take care of keyboard interface, physics and letting mpf know which switches have been hit. With this interface you can (sort of) white board the table before you start investing in a physical game.

Here is a video of game play in the mpf vpx interface. I could only get one audio track to record so you'll only hear the mpf sounds. You won't hear any vpx sounds like solenoids firing, ball roll or anything else that vpx would play. Also because my video card was driving three monitors and trying to record, there is a bit of lag to the game play (which accounts for some of my poor play). Lastly vpx has a ball control feature which is super helpful in testing hard to hit shots. Unfortunately the SOUL lights are shifted by the flippers and the flippers on my vpin cab also control the left and right ball motion so there's a little funkiness there. Additionally if you jam a vpx ball (with ball control) into a drop target or stand up, you can generate multiple hits which you will see late in the video. This would never occur in normal vpx play but I figured you would't want to watch an hour long video...

Now that I knew the software is working I needed to start working on the hardware side of things. I took a look around at the various options for driving the table and wanted to go with the least expensive stable option which lead me to the Open Pinball Project. I was a little confused at first because it looked like there was a change in the small driver boards because the original boards are now obsolete.

Through more searching I came across a new prototype board that was looking for beta testers called the Cobrapin Board designed by @cobra18t. The details of the board can be found at this site in the mpf docs.

https://docs.missionpinball.org/en/dev/hardware/opp/cobrapin/index.html

The really slick thing about this board is that instead of multiple boards for power, switching, lighting and solenoid control, this is a all in one solution. I ordered one of these configured for use in a 24vDC table. Cobra18t has been great to work with and has been very helpful in answering my questions about this project.

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This table was designed by Onevox and A_Bord did quite a bit of blender and other graphical updates. Great to see them following along!

Next step was to find a suitable donor machine. My original thought was to pick up a cheap non-working EM so I contacted the guy that I've bought all of my rehab projects from to see if he had any.

https://vpinball.com/forums/topic/just-bought-my-first-table/
https://vpinball.com/forums/topic/darling-restoration/
https://vpinball.com/forums/topic/pirate-gold-restoration/
https://vpinball.com/forums/topic/grand-tour-bally-1964-restoration/

He said that he had an Allied Leisure Suit Thunderbolt from 1976 that powers up and plays for $150, so I hopped in the van and drove to Northern Illinois to pick it up. The cab is in good shape and well built, once I got it home the game powered up and played flawlessly as advertised. It has a really nice chime unit in it that I'll sell off as well as the MPU, score and credit displays. The downside of ALI is that they use white nylon plastic where others use steel. There's a cheap feel to the components which I'm sure was a big part of their business model. The good news is that most of the components are still functional after 52k plays and 44 years so they exceeded their intended life span.

The table has pretty much everything except for the lockdown bar. This is unfortunate because ALI uses a bar with pins on it like Bally did in the 1960's so that is going to be hard to find. I should be able to use the pop bumpers, flippers, slings, three stand up targets, posts, arch and apron so that's a good start on parts.

ALI's artwork is pretty bad and the game play looks to be so so. This is a good thing because it doesn't make me feel too guilty taking a fully functional table and gutting it out.

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My current plan is to take the VP playfield graphic to a print shop and have it printed at full size. I'll glue that down to the plywood and hand cut a whiteboard from that so that I can test out the machine before making the final version. If the white board is good, it will become the final version.

Another option is that I know a guy you has a CNC machine that can accept a full 8' x 4' sheet of plywood. I could make a gcode file with my Vectric software and have him cut it for me but that would probably add a fair bit of cost.

mbwalker that sounds like a good plan because you could do various shapes with it. I was initially thinking Forstner bit but that will be hard to control and manhandling a playfield with a drill press is probably more work than it's worth. BorgDog how did you do your inserts on Nobs?

This looks like it could be pretty useful for boring the counter sunk insert pockets so long at the chuck and shafts don't have much run out to them.

https://www.amazon.com/Milescraft-1318-DrillMate-Drill-Guide/dp/B014A1Z92I/ref=sr_1_2

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Nice weather, November and Wisconsin don't usually go together so I took advantage of today's temps in the low 70's and cleaned up and painted the legs. Since I have a nice set of black leg bolts left over from a previous project, Cuphead will get black hammer painted legs.

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Yes the bike stand is like a lot of tools, once you have one you'll find other uses for it.

Can anyone recommend these two options for insert and GI lighting respectively. I need to work with 5v DC.

https://smile.amazon.com/dp/B01DC0J0WS/

https://smile.amazon.com/dp/B01AU6UG70/

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As I mentioned in my earlier posts, one of the goals of this build is to keep the costs down. That means reusing parts from the machine whenever possible so today's post looks at converting the cheap looking ALI 3" flippers into 2" flippers. I say cheap looking because although they are all plastic, they are still stable and functional after 52k plays so maybe ALI was on to something?

ALI uses lots of nylon plastic in their design, the flippers are no exception. I spent some time looking at them to figure out if there would be a way to modify them. These flippers have a star shaped end that fits into the linkages to drive the flipper. On the plus side, this only gives a few possible orientations, should make a very strong joint and avoids the issue with the set screw making an indent in the shaft that prevents setting the flipper orientation just right. The downside is that I'll have to rotate the mech below the playfield to get the correct orientation. Since this is a home brew and there looks to be lots of room, I don't see this as a big issue.

I had some 2" bats left over from another pin and some 3" metal bases so I marked up the metal bases and cut them to fit the 2" bats. I removed the top pins on the metal bases, drilled a receiver hole and tapped the hole for the screws that hold the bats on. I then marked the base shaft length and cut to a length that would fit into the ALI flipper shaft.

The ALI flipper bat and shaft are an all-in-one unit so I sawed off the bat and center drilled a hole that could receive a metal base. Because of the amount of stress that these will see, I figured there would be no stronger joint than a thread so I cut a 1/4 20 thread into the shaft and drilled and tapped the hole in the plastic shaft to receive this thread.

When these are mounted on the white board i'll make fine adjustments to the bats with thin washers and then epoxy the base and shaft into their final position. This might work great, it may fail spectacularly, that's what the white board is for...

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We'll see how the flippers work out, thanks for the cnc info. I do a fair bit of cnc work but my machine is not large enough to do a playfield, even in multiple passes. I should be able to hand make the pf without too much difficulty, this is my side business http://www.semillerguitars.com/

More clean up, painting and fixing. Pulled the coin door while the good weather lasts and gave it a coat of black hammer paint just like the legs. At the advice of BorgDog I ordered a vibratory tumbler for polishing small parts. This big stuff works out fine with my bench top grinder and a wire wheel. Here's a photo of the feet being polished because no one wants rust marks on their carpeting.

The pop bumpers are made of, wait for it... plastic of course. Here's a shot of one of them assembled. Unfortunately one of them must have had something drop on it because there is a perfect knockout of the center with the crack lines shaped like a blow to the top. Fortunately it pops back together very tightly so the question was "how to stabilize it." Before I popped it back together I was thinking 3D printed splint but once I saw how nice it went together I thought "epoxy pour."

I have some two part West System epoxy left over from the last kayak that I built so I taped the cracks on the top surface and mixed a small cup (a little heavy on the hardener) and did a pour. I now have a very solid hockey puck. I'm thinking of doing the same to the other two bumpers because it's pretty easy to do now while everything is apart.

The plastic part that squeezes the ball away from the bumper needs to be measured to see if it's the same size as the metal ones because if it is, I think I'll switch those out.

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The Brains of the Operation was the next step. When my son rebuilt his gaming desktop this fall I made sure to keep his motherboard, processor and graphics card for future use. Several years ago these were the original computer components for my virtual pin cab before that got upgraded to its current configuration.

The biggest problem with this step was that the Windows 10 OS was on a hdd and I wanted to transfer it to a solid state drive for Cuphead. I had a small ssd lying around but it didn't have an OS so I spent the better part of a day trying to transfer or clone the hdd. In the process I screwed up the boot partition on the hdd and I ended up formatting the ssd and did a fresh install of Windows 10 using an key from a computer that is no longer in use.

Here are photos of the computer mounted on a piece of plywood running mpf Cuphead on a TV.

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mbwalker thanks for the rust removal tip!

Power, that's the next thing on my list.

There are a lot of ways of powering a cab and when I first looked at this aspect of the project I really didn't know which way to go. I started off by measuring the amperage draw of the various coils in the cab while TB was still functional. The results that I got were jaw dropping. The primary coils on the flippers drew a massive 8.5A while the hold coils drew 1.5A. The drop target reset coils drew 4A while each of the other coils (pop bumpers & kickers) drew 3A each.

If there was a 2 ball multiball a maximum of up to 23A or more (both flipper hit at the same time while 2 other coils go off) could be drawn at 35v for a whopping 805W. Coils can draw even more than their stable current draw when they start up so power consumption could be massive. I knew that the fuse ratings for the solenoids was a fraction of this current draw so I reached out to BorgDog and cobra18t for advice.

Borgdog told me that his TNA uses a 48v 600W power supply (12.5A) and it runs perfectly. This reassured me that since professional pinball designers think that 600W is enough power then my calculations don't apply in the "real world." Cobra18t told me that mpf uses clever software devices to try to space out the firing of coils and it also limits the length of time that a coil fires to reduce power needs. His Cobrapin board also has some beefy caps on the power side of things that can discharge to help out when current draws are large.

Armed with all of this info I knew that I could either buy switching power supplies or reuse what I already have. Since the machine has a great transformer in it that is already driving the coils at an unregulated 35v DC I decided that its 880W (110v with 8A main fuse) would be more than enough for the cab's power needs. In following with a main theme of this project, this was also the cheapest option.

First off I checked out the big electrolytic caps in the machine and two of them had ESR's of over 6 Ohms so they had seen better days but the one that had a 2W bleed resistor across its terminals has a sprightly ESR of .14 Ohms so it still reads that it is in great shape. I reused that cap on the 35v power supply and bought a $12 20A 300W buck converter for the 5v output. I didn't put a smoothing cap on this circuit because the buck converter can take care of smoothing the output.

I pulled all of the other power supply feeds from the "power board" since I didn't need 180v, 17.5v, 6.5v or any other outputs. I then moved components around on the board to make better use of the space and soldered a lead onto the 6.5v AC tap on the transformer. This tap goes to a fused bridge rectifier and the full wave rectified output goes to the buck converter.

Here's a photo of the power supply with a meter showing the 5v DC output. I should also mention that I replaced the old fuse holders since it is just a matter of time before they start breaking off wings. Also there is a single point grounding terminal just above the big cap.

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Thanks @jabdoa, can you link this post to my mpf build link?

Thanks, I'm getting closer to actually being able to beta test for you.

The cab is not the most exciting part of any project but it's got to get done. ALI uses lots of different materials at least in this cab. There's good old fashioned plywood as well as particle board and the new modern space age material (at least in 1976) MDF. I've rehabbed cabs from Bally, Williams and Chicago Coin and one thing that's different about this cab is that the paint has an orange peel texture to it. Using this plus the dark grey splatter pattern really did a great job at hiding the imperfections in the plywood of the cab. I didn't notice many of the defects until I got a few coats of white on the cab and head.

One thing that I did a little different this time is that I used my flat bed hoist to hold the cab. This is working out great because it lets me move the cab around the workshop which is really nice when you have a shop that is as small as mine. Much better than the saw horses that I've used in the past. I did some bondo repairs to chipped sections as well as remove the cab's partial serial number.

I also got around to disassembling the other two intact pop bumpers and did epoxy end pours on them. Today I picked up a set of three metal "ring and posts" on Ebay to replace the plastic ones. From my crude measurements from my Williams Tropic Fun, the metal posts may end up being a little too long so I may have to shorten them and cut additional threads.

I'm planning on making custom "Goblett" flippers so I wet sanded off the red hot press "FLIPPER" graphics from each of the 2" bats. I'll use my Cricut to cut a vinyl stencil for these.

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The flippers will be a stencil so I can match the paint colors with Createx. Currently I'm working with A_Bord on the cab art. My plan is to try to mimic the art style of pins from the 60's to 70's so three color (red, white, blue), splatter background and stencils with small stand offs to get a little overspray around the edges. These are what I'm going with for the cab and head, the front will get two stacks of chips on either side of the coin door.

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